& btthreshold()
 
  Syntax: btthreshold(<skill>)

  This function returns the threshold constant. This constant is one 
  of the factors used to calculate the number of points required in 
  the XP pool of <skill> to improve the skill's base-to-hit by 1.
 
  Error Messages:
 
  * If <skill> is not valid the function will return #-1 ERROR 
 
  Example:
 
  > think btthreshold(medtech)
  999999
 
	Note: The amount returned by btthreshold is NOT the only factor in 
	determining if a player will 'level up'. Further calculations 
	modify the required XP dynamically.